Charged cosmological black hole

Abstract

The cosmological black holes are black holes living not in an asymptotically flat universe but in an expanding spacetime. They have a rich dynamics in particular for their mass and horizon. In this article we perform a natural step in investigating this new type of black hole: we consider the possibility of a charged cosmological black hole. We derive the general equations of motion governing its dynamics and report a new analytic solution for the special case of the charged Lematre-TolmanBondi equations of motion that describe a charged cosmological black hole. We then study various relevant quantities for the characterization of the black hole such as the C-function, the effect of the charge on the black hole flux and the nature of the singularity. We also perform numerical investigations to strengthen our results. Finally we challenge a model of gamma ray burst within our framework. * Rahim.Moradi@icranet.org † clement.stahl@pucv.cl ‡ j.taghizadeh.f@ipm.ir § xue@icra.it 2

Constraints on tidal charge of the supermassive black hole at the Galactic Center with trajectories of bright stars

“…Among different theoretical models have been proposed for the Galactic Center different black hole models are rather natural. Perhaps, assumptions about a presence of electric charge in the metric do not look very realistic because a space media is usually quasi-neutral, but the charged black holes are discussed in the literature see, for instance [70] and references therein. Moreover, a Reissner -Nordström metric could arise in a natural way in alternative theories of gravity like Reissner -Nordström solutions with a tidal charge in Randall-Sundrum model [2] (such an approach is widely discussed in the literature).…”

Cosmological solutions with charged black holes

“…where d and d FLRW are given by equations (32) and (33). This ratio is only a function of the charge to mass ratio of the black holes q/m, and reduces to the measure of cosmological back-reaction studied previously in ref.…”

“…Most of them have considered vacuum solutions of Einstein's equations, but some have involved generalisations that include a non-zero cosmological constant [11,14,21,30] and the inclusion of matter modelled as radiation and a scalar field [11,22]. In this paper we focus on including electric charge, so that Reissner-Nordström-like black holes [33], or other types of charged astrophysical bodies [34], can be included in cosmology. As far as we are aware, this is the first treatment of cosmological backreaction in the presence of non-zero electric charges.…”